This invention relates to a ceiling vent for dispersing air into a room. More particularly, this invention relates to a ceiling vent that diffuses hot or cold air along the top of a room for best dispersion into the room volume and evenly disperses variable-velocity air currents in laminar flow.
Perhaps the most critical component of a heating or cooling system in a home or office is the vent or diffuser for dispersing the heated or cooled air as evenly as possible throughout the room. If diffusion of the air throughout the room is uneven, then pools of air of different temperatures may form at various locations in the room. This is an inefficient way to heat or cool a room and can be uncomfortable to persons who live or work there.
The best known way to diffuse air in a room is to redirect the air in a laminar flow at the top of the room. This sheet of air then mixes with the ambient air to achieve relatively even heating or cooling without pooling or dumping in certain locations. The distance that air moves at a given velocity, or air flow throw, will vary with the velocity of the air that moves through a vent. Thus, differences in velocity will affect the evenness of air dispersion in a room. It is highly desirable to maintain constant the air flow throw from a vent, despite variations in initial air velocity, to control the even mixing of air in a room. A fluid, such as a current of air, that is moving at some velocity along an adjacent surface tends to cling to that surface. This is because low pressure is created below the current, in the case of a stream of air moving along a ceiling, thus lifting the current of air upward against the ceiling. This phenomenon, the Coanda effect, increases the air flow throw and thus the dispersion of air in a room.
One proposal for maintaining even mixing of air from a ceiling diffuser involved a device mounted on conventional ceiling tee bars and containing a thermostatically controlled motor to position air flow control vanes to manage variable flows of conditioned air (U.S. Pat. No. 3,848,799). Another device handled variable air flows by pumping air into a bladder to regulate the area of air discharge (U.S. Pat. No. 3,434,409). Other devices of general interest had to be manually adjusted to handle different air flows (U.S. Pat. Nos. 4,475,446 and 4,008,653). These devices all suffer the disadvantages of mechanical complexity or the need for manual adjustment to handle variations in air flow.